How can you tell the ratio of the differential? The window sticker say 11.50 Anti-Spin. It does not say if it is 3.73 or 4.10. The truck is a 2005 with a build date of Oct 04. It does have the trailer tow group if that helps. This a truck I am looking at buying.

 

Look on the truck data tag. Glovebox I think. 11.5 refers to the size of the rears, not the ratio.
Window sticker will also give details.

 

The window sticker does not indicate what the ratio is. My last truck the sticker did say but this one does not.

 

It's posted in the Glove Box of the truck!

 

Found it, thanks.

 

the window sticker will list it as a specific upgrade of $50 for the 4.10 gears or it is buried in the off-road package which is also listed on teh window sticker. if you do not have either one, you have 3.73.